1. Field of the Invention
This invention relates to semiconductor devices of the type having a support on which a semiconductor chip is mounted and a plurality of leads electrically connected to the semiconductor device and, more particularly, to a lead identifier which assists identification of a specific lead in the plurality of leads.
2. Background Art
Semiconductor devices are commonly constructed using lead frames, each consisting of a support and a plurality of leads spaced around the support. A semiconductor chip is mounted on one surface of the support. Conductive elements, such as wires, electrically connect between the support and the multiple leads. The semiconductor chip and wire leads are resin sealed. The support and leads are exposed at the bottom/back side of the completed semiconductor device and are not exposed at the top/front side of the completed semiconductor device.
It is helpful to the user of such semiconductor devices to be able to identify at least one specific lead in the plurality of leads. For this purpose, conventionally an identification mark has been placed on the top/front of the semiconductor device in a manner to assist identification of a specific lead or leads. Since the location of a specific lead or leads on the bottom of the semiconductor device is identified by the mark on the top of the semiconductor device, while working at the bottom side of the semiconductor device, it may be difficult to identify a specific lead or leads through the identification mark.
In one form, the invention is directed to a semiconductor device having oppositely facing first and second sides. The semiconductor device has a support exposed at the first side of the semiconductor device, a semiconductor device mounted on the support, and a plurality of leads connected to the semiconductor device. A lead identifier on the support is visible at the first side of the semiconductor device and assists identification of a specific lead in the plurality of leads.
In one form, the support has a peripheral edge and the lead identifier is at the peripheral edge.
The support has a thickness between the first and second sides. The lead identifier may be formed fully through the thickness of the support or only partially through the thickness of the support.
In one form, the support has a polygonal shape with a plurality of corners and the lead identifier is at one of the corners.
The lead identifier may be formed in the support by etching, stamping, or the like.
In one form, the semiconductor device has a tie bar projecting away from the support and the lead identifier extends from the support into a portion of the tie bar.
The invention is also directed to a lead frame assembly for a semiconductor device, which lead frame assembly has oppositely facing first and second sides. The lead frame assembly has a support having a surface on the first side of the lead frame assembly for mounting a semiconductor chip, a plurality of leads spaced from the support, and a tie barnetwork connecting the support to the plurality of leads. The lead frame assembly has a lead identifier at the second side of the lead frame assembly which assists identification of a specific lead in the plurality of leads.
The invention is further directed to a lead frame for a semiconductor device, which lead frame has oppositely facing first and second sides. The lead frame has a support having a surface on the first side of lead frame for mounting a semiconductor chip and a plurality of leads spaced from the support. The lead frame has a lead identifier at the second side of the lead frame which assists identification of a specific lead in the plurality of leads.